Two-seal sewer-gas trap



(No Model.)

- G; H. RHETT.

TWO SEAL SEWER GAS TRAP.- No. 413,307. Patented 001;. 22', 1889..

Ewe/70601:

N. PETERS. Phdlu Lilhogmphtr. wm'u c.

" UNITED STATES PATENT OFFICE,

CHARLES H. RHETT, OF BALTIMORE, MARYLAND.

TWO-SEALSEWER-GAS TRAP.

SPECIFICATION forming part of Letters Patent No. 413,307, dated October 22, 1889.

Application filed January 22, 1889; Serial No. 297,217. (No model.)

To aZZ whom it may concern.-

Be it known that 1, CHARLES H. RHETT, of the city of Baltimore and State of Maryland, have in vented certain Improvements in Two- Seal Sewer-Gas Traps, of which the following is a specification; and I do hereby declare that in the same is contained a full, clear, and

exact description of my invention, reference being had to the accompanying drawings, and b to the letters of reference marked thereon.

My invention relates. to improvements in and an outlet orifice in the top and the bottom, and provided with a gravitating ballvalve, having its normal seating upon the outlet-orifice, but capable of floating also, and designed to close both orifices, as the operations of the trap may require. Attached to the lower orifice is a curved pipe having a liquid seal carried upward to a bend a little above the level of the base of the chamber, defining the water-level in such a manner as to inundate its bottom and extend the liquid seal into it. It is not intended that its depth should besufficient to float the valve, nor to interfere with its close seating, but merely to afford it a support, when required, to float on a discharge of liquid occurring,'and.to proteot it against the suction of an empty outlet-orifice. Thus, whilethe chamber is waterholding to the extent described, the larger portion of it is practically dry, and only the lower side of the valve is immersed. It is important that the valve-seatin g, particularly of the outlet-orifice, should be rigid and not raised to extend intothe chamber, as that interferes with the rapidity of the venting and causes the, accumulation of sediment. The valve should be twice or more in diameter than this orifice, to render its resistance sure against the constantly-recurring suction caused in it by the liquid outflow. The orifices are not necessarily in alignment with each other; but when placed out of line the floor and the roof of the chamber should be The operation of my invention under the foregoing conditions is easily understood.

The advantages of my construction consist 7 partly in the independent yet co-operative dual character of the seals -by valve or by water-where siphonage is rendered impossible, because it would only draw the valve B closer to its seat, and where if the water seal is lost by evaporation the valve seal would be maintained byits gravitation alone. Here, also, the pressure of the valve B against the orifice D checks regurgitation; but the device by which the floor of the valve-chamber is inundated, so as to give support to the valve and to diminish the suction, removes the great difficulty of venting liquid into a vertical outlet through an orifice normally occupied by a gravitating valve."

I do not confine myself to the exclusive use, of the curved pipe to establish the liquid seal in the chamber, but willadopt any other convenient construction for that purpose.

Having thus described my invention, I claim Letters Patent for 1. A sewer-gas trap consisting ofa chamber having an inlet-orifice at the top and an outlet-orifice at the bottom, a trap connected with the outletorifice having its outlet above the floor of the chamber, but below the main portion of the trap, and a buoyant and gravitating valve having sufficient weight to seat against the outlet-orifice when the chamber is full only to the level of the outlet of the trap and sufiicient buoyancy to move from its seat when additional liquid enters the chamber, substantially as described.

2. In combination with a sewer-gas trap consisting of a chamber having an inlet-orifice at the top and an outlet-orifice at the bottom, and a trap connected with the outletorifice having its outlet above the floor of the chamber, but below the main portion of the trap, a buoyant and gravitating valve of more than double the diameter of the outlet-orifice upon which it is seated, whereby the valve,

10 closing the outlet by its gravitation, is ena- 

